[Value of pulse indicator continuous cardiac output monitoring of cardiac function in septic shock patients: a prospective study].

OBJECTIVE: To investigate the value of employing pulse indicator continuous cardiac output ( PiCCO ) for cardiac function monitoring in patients with severe septic shock.

METHODS: A prospective observation was conducted. Thirty-six septic shock patients in Department of Critical Care Medicine of Peking University Third Hospital admitted from August 2011 to December 2013 were enrolled. According to the degree of severity, the patients were divided into PiCCO monitor group and routine monitor group. The PiCCO monitor provided a continuous assessment of fluid resuscitation, vasopressors and inotropes infusion in the patients with severe septic shock. The following cardiac function parameters were assessed in severe septic shock patients on the 1st and 3rd day after intensive care unit ( ICU ) admission: cardiac index ( CI ), global ejection fraction ( GEF ), rate of left ventricular pressure increase ( dp/dt max ), echocardiography, and blood troponin T ( TNT ) and B-type natriuretic peptide ( BNP ). The central venous pressure ( CVP ), mean arterial pressure ( MAP ) and the time reaching their standard values, and the norepinephrine dosage and 3-day fluid balance in severe septic shock patients were compared between milrinone and non-milrinone usage groups. The severity degree and outcome were compared between PiCCO monitor group and routine monitor group.

RESULTS: There were 15 patients in PiCCO monitor group and 21 in routine monitor group among 36 septic shock patients. (1) In 15 patients with PiCCO monitoring, the patients with decreased CI, GEF, and dp/dt max accounted for 40.0%, 93.3%, and 33.3% at 1 day after ICU admission, and accounted for 60.0%, 93.3%, and 60.0% at 3 days after ICU admission, and it showed that CI, GEF, and dp/dt max was not improved at 3 days after ICU admission. Echocardiography showed that 35.7% patients had lower left ventricular ejection fraction ( LVEF ) at 1 day after ICU admission, 71.4% and 71.4% of patients, respectively, had lower early diastolic mitral flow velocity/early diastolic myocardial velocity ( E/Em ) and early diastolic mitral flow velocity/end diastolic mitral flow velocity ( E/A ). Three days after ICU admission, 80% of patients with low LVEF value turned to normal, and diastolic dysfunction was ameliorated in 50% patients. At 1 day after ICU admission, higher TNT was found in 92.9% of patients, higher BNP in 100% of patients, and 3 days after ICU admission, 71.4% and 78.6% patients showed a decrease in TNT and BNP, respectively. (2) In PiCCO monitor group, there were no significant differences in initial CVP, MAP and their time reaching standard values, norepinephrine dosage between milrinone group ( n = 8 ) and non-milrinone group ( n = 7 ). However, 3-day intake of liquid in milrinone group was significantly higher than that in non-milrinone group ( mL: 8 324±3 962 vs. 4 372±2 081, t = -2.362, P = 0.034 ). (3) Compared with routine monitor group, there was a significant elevation in acute physiology and chronic health evaluation II ( APACHEII) score, sequential organ failure assessment ( SOFA ) score, duration of mechanical ventilation, length of ICU stay and 28-day hospital mortality in PiCCO monitor group [ APACHEII score: 20.67±6.15 vs. 14.71±4.67, t = -3.304, P = 0.002; SOFA score: 9.53±3.00 vs. 7.52±1.97, t = -2.433, P = 0.020; duration of mechanical ventilation ( hours ): 132 ( 54-310 ) vs. 63 ( 14-284 ), Z = -2.295, P = 0.022; length of ICU stay ( days ): 7 ( 4-15 ) vs. 5 ( 1-14 ), Z = -2.360, P = 0.018; 28-day hospital mortality: 26.7% vs. 0, P = 0.023 ].

CONCLUSIONS: With the use of the PiCCO hemodynamic monitoring in patients with severe septic shock, more comprehensive values of blood volume, systemic vascular resistance and cardiac function can be obtained for guiding fluid resuscitation and selection of vasopressor and inotropic drugs.